Common brand names include Eltroxin, Euthyrox, Eutirox, Letrox, Levaxin, Lévothyrox, Levoxyl, L-thyroxine, Thyrax, and Thyrax Duotab in Europe; Thyrox, Thyronorm in South Asia; Unithroid, Eutirox, Synthroid, and Tirosint in North and South America; and Thyrin and Thyrolar in Bangladesh....